Apparatus for producing pulsating air pressure



R K SCHMID El' AL APPARATUS FOR PRODUOING PULSATING AIR PREhSSURB UJI Patented oct. 27, i925.

Unirse STATES:

' 1,559,284 PA'TF-NT?? OFCE? RICHARD' KARL'SCHMID AND WALTER PAUL WEZEL, OF STUTTGART, GERMANY. ,i

Applicationvled June 25, 1924. Serial No. 722,404.

To all whom it may concern.:

Be it known thatv we, RICHARD KARL Soi-1Min, a citizen of the Republic of Germany, and a resident of Stuttgart, Germany, and VALTER PAUL VEZEL, a citizen of the Repub-lic of Germany, and a resident of Stuttgart, Germany, have invented certain new and useful Improvements in Apparatus i for Producing P-ulsatingAir Pressure', of

which the following is a specification.

Alternating or pulsatingair pressure Aproducers Vare known in which the admission anddischargeof air are controlled by slots, and alternating or pulsating air pressure producers are also known, in which the pressure and suction air are controlled by one valve. i f

The present invention is characterized in that the valve is utilized only for controlling the discharge of air, whilst the air drawn in, is admitted through inlet slotsfin vthe compressor cylinder.

This arrangement has the advantage that a considerably larger cross-section is available for the suction than for the discharge, since practically the whole circumference of the cylinder is available for the suction port. This difference in capacity of the twodevices for the admission and discharge is necessary, as the suction takes place with a very imperfect vacuum of, say, .about 0.5 atmosphere, whilst during the discharge, the air is compressed to about 1.2 kto 1.5 atm. In the latter case the valve may therefore be considerably smaller. This is aA great advantage, since the clearance causedby the connection pipe tothe valve becomes considerably smaller.

On the other hand, another andA decisive advantage of the valve construction for the air dischargeis that it is possible at any moment to fix the timing of the valvey opening and closing for the discharge entirely independently of the movement of the pis-y ton, by means of suitable cams, whilst for instance in the case of control exclusively by slots, one is positively tied to the movement of the air pump piston.

Practical experience demonstrates that the maximum output of thehainmer is dependent directly on the beginning and the duration of the discharge, relatively to the dead centre position of the piston, and as the most vfavorable moments of opening and closingcannot be attained by means of slots, for kinetic reasons, a material improvement is Vachieved-'by the use of the labove vmentioned controlled valve for the Aair discharge with simultaneous useiof port belts in the 'cylinder for the air admission.v

A construction according to the invention is illustrated in the accompanying drawing in which- Figure vl is a vertical central section through the air pulsator, and

Figure 2 is an outside elevation of the side situated on the left hand in Figure 2, the cover being removed.

The air pulsator illustrated is intended to produce alternate depression and compression in the hose pipe leading to a pneumatic hammer. To achieve this result the shaft 0, which is driven in a mannerfthat neednot be described, operates the piston el as for example by means of a crank connection with the piston. At the left hand outer. end of the shaft c is arranged a. valve rod driven bya cam disc e and sliding in aguide g. At each revolution, the valve is opened and closed twice, once for the air discharge, and the second time, for suppleinenting the atmospheric air drawn in through the air slots, for the air admission.

As, however, for the air inlet slots the wholeV annular surface of the cylinder is available, as already stated, one camV which provides for the additional air admission vmay be suppressed. In any case it is immaterial forthe substance f the invention.

From the foregoing description considered in connection with the accompanying drawings, they construction and the advantages of the invention will be readily understood. Although we have herein described some practical Vembodiments of our invention, which have given highly satisfactory results in actual use, it is nevertheless to bc understood, that the essential features of our improvements might likewise bel embodied in numerous other alternative constructions. Accordingly therefore, the privilege is reserved of resorting to all such legitimate changes in the form, construction and relative arrangement of the several parts as may be fairly considered within the spirit andv scope of the invention as claimed.

Having now particularly described and ascertained the nature of our said invention and in what manner the same is to be performed, we declare that what we claim is z- 1. In an apparatus for producing pulsating air pressure, in combination, a cylinder,

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a valve, apiston moving in the said eyiinder, means for driving the said piston and the valve, the cylinder being' provided With slots for admitting air to the cylinder by suction, the compressed air leaving the eylinder through the said valve.

2. In an apparatus for producing pulsatingair pressure, in combination, a Cylinder, a valve, a piston moving in the said Cylinder, ineens for driving the Said piston and the valve7 the cylinder being provided Wit-h slots 'for admitting air thereto byvsuetion,

the Compressed air leaving the cylinder through the said valve, the Valve heing` operated twice during each double str-oke of the piston, in order to additionally admit air during the one stroke, and to exhaust the Compressed air during the other stroke of the piston.

n testimony that they Claim the foregoing as their invention, they have signed their naines.

RICHARD KARL- SCHMID; VALTER PAUL VEZEL. 

